Um, not meaning anything rude here, but I see a breach here for hackers(Hack disrupts everything). If Everyone can go and see the naughty players in Jail through one entry point, then there's a chance for them to get out through a wall-walking hack which only admins have if they're hackers.
Suggested solutions : I think there should be an admin in the Jail during that time or only visiting them when an admin permits and teleports them to the Jail.
Besides this, the other ideas are great  |
Maybe instead of you being inside the same room as the convicts, what if it mirrored the image of the people in the actual cells into the apparent cells, rather than actually being in the cells.